The present invention relates to a control lever assembly, and more particularly, to a control lever assembly for use in a vehicle transmission control system.
An electronically controlled transmission, such as a powershift transmission or an infinitely variable transmission (IVT), requires an operator control device, such as a shift control lever, for generating control signals which are supplied to an electronic control unit which, in turn, controls the transmission. For example, U.S. Pat. No. 6,247,378, issued 19 Jun. 2001 to Newendorp et al., describes an operator control for an IVT. Such shift control levers are subject to being inadvertently bumped or knocked out of their park or neutral positions. Such shift control levers have typically employed space-consuming complex and circuitous travel paths in order to avoid the lever being inadvertently moved into a position which commands vehicle movement. It is desired to have a simple shift control lever assembly which prevents inadvertently lever movement.
Accordingly, an object of this invention is to provide a compact control lever assembly which resists inadvertent lever movement.
These and other objects are achieved by the present invention, wherein a control lever assembly for a vehicle transmission includes a housing which supports a guide plate having a slot and a recess formed in a central portion of the slot. A carrier member is pivotally coupled to the housing about a pivot pin. A lever has a shaft which is supported by the carrier and which is rotatable and axially movable relative to the carrier. The lever has a knob which is mounted on an end of the shaft and which is received by the slot. A spring is coupled between the shaft and the carrier and is biased to rotate the knob and to urge the lever towards the pivot pin. When the knob is in the slot and outside of the recess, the slot walls prevent rotation of the knob and maintain the lever in a first rotary orientation. When the knob is moved into the recess, the spring is automatically able to rotate the knob and lever into a second rotary orientation. When the knob is in the second orientation, the recess walls are engagable with the knob to prevent the lever from being pivoted about the pivot pin. The housing includes a detent member which engages detent rollers mounted on the carrier to releasably hold the lever in selected positions in the slot. The knob may be manually moved axially over an abutment formed by a wall of the recess and rotated into a third rotary orientation.